The hydroxyl groups can be changed into esters , ethers , acetals and ketals, etc.最常用的羟基保护基可归纳为三类:酯类 、 醚类和缩醛或缩酮类.Eight acetals ( Ketals ) were synthesized under the optimal conditions.在最佳条件下,合成了八个缩醛 ( 酮 ) 化合物.The yields ...
她用偷来的绷带迅速把他绑紧，并塞住了他的嘴。She trussed him quickly with stolen bandage, and gagged his mouth.射击一开始,大家都用手指塞住耳朵.Everyone put their fingers in their ears when the shooting started.她用脱脂棉塞住了耳朵.She stuffed her ears up with cotton w...
to make cynically callous.使冷漠They cynically tried to trade off a reduction in the slaughter of dolphins against a resumption of commercial whaling.他们见利忘义地试图以减少屠杀海豚数量作为交换条件，重启商业捕鲸。I firmly believe our strategy is being de...
This helps to ripen new growth and makes it flower profusely.这有助于新生发植株的成熟，令其开出繁茂的花朵。Time will soon ripen.时机将很快成熟.The pears will sweeten as they ripen.梨子熟了就会变甜....